relo999

Detached the RF board, no change. So not a problem on the RF board...

I've got one of those nice "blackscreens of can be anything" on my recently acquired colecovision... But I can't seem to fix it. It is a revision D PAL system. I suspect it having a short somewhere on the 5V line. Powered off it gives 5V but turned on 1.38V. And my guess is low voltage to chips = black screen. -Cleaned it at least twice with alcohol. -Jumped the powerswitch, but that was a no go. -I've checked the PSU (its one of those plastic bricks unable to work on if I wanted) but that seems to be fine, as I could power a gameboy over the 5V line of the PSU. -I've replaced the RAM chips with CD4516BE using the 5V mod, thinking one of those chips might have caused the short. -Recapped it but with similar result. (there was some lower resistance between ground and 5V line, but that was gone after but apart from that nothing changed) -Checked if it could be on the RF board, but that seems to get it's 5V from the 12V line. So what else might cause this problem, and if its a short how can I find it?

The vectrex entered public domain in the mid-90's

It seems that the transistor TR4 is broken, but what transistor do I need to replace it?

I'm asking as I don't seem to get any voltage after the left side of the DC jack, or after TR3.

I think I might have found the problem. The diode give voltage before it the arrow-ish part ~0.2V and after the input voltage ~14V. So should there be a voltage difference between both sides of the diode (D1)?

BTW is there an easy way to check the connections on the power board?

I hope these are alright?

I just noticed my own stupidity. I've checked the whole power board and I aperently checked the wrong thing. The actual voltage regulator says ~0.1V in / 0.01V~ out. Which it obviously shouldn't, on both sides, so there seems to be something else wrong...

It looks like this, how can I remove that and replace that? And could I just replace it with a regular 5V 7805 voltage regulator?

the voltage regulator in and out all say ~13,5V and the fuse ~14V. How can I check if the other boards get any voltage?

I've taken a look inside again, this time with more knowing what I did. The adapter does give power to the board, or at the very least partially, as the voltage regulator does work (14 in / 13 out). Apart from that I've dissembled the whole system (except for the CD area) to for something out of the ordinary, nothing much except for some slight roughness of the power board on the underside under the heat-sink and the battery being replace and soldered with wire into place (but that seems to just fine from the looks of it).

before and after the fuse, both before (and both after) the fuse and some random point's in the system.

I've did some extra checking as I expected maybe the fuse blew again by repeated attempts at rebooting, which was just just fine. But the thing I did notice was odd as there was no voltage at the fuse (at least to me seemed odd I'm not a electric engineer or might be using the voltage meter incorrectly)

I've recently acquired a asian model 1 sega CD which at first sight the only problem with it was the fuse, but now I've replaced the fuse but it still doesn't power on. Occupationally it flickers its lights for a second (about once every 50 times) but nothing more. I do use a regular (euro) megadrive 1 AC adapter for it but for the megadrive it self I use a AC adapter for the model 2 master system (which seems to work fine on just the megadrive).

I recently started to attempt at fixing a SNES for a friend of mine but he had this problem: strange glitchy display (but still interact-able to some extend) but there seems to be nothing wrong with audio and in some games screen effects. All games I tried I have tried on my own SNES with no problem but when put in my friends SNES. I've tried cleaning the inside (which was filthy to say it nice), cleaning and bending the connector but both have failed to give any effect. Also apart from the filth pre-cleaning there seems to be nothing wrong internally. How can this be fixed or is it practically dead? Some examples: Starfox (intro) F-Zero (start-up) Vortex (everything)

I've also noticed the location of the fuse is diffrent from pictures I saw of it's location, but that might be because it is an asian sega CD. Or should all sega CD's model 1's be the same internally?

I've recently purchased a Sega CD model 1 from ebay that doesn't power up, I've checked the fuse and 3 out of my 5 tests says it's the problem (most likely were the other 2 just me failing at using the multimeter properly due to it being crammed). But due to it being in such a crammed space how can I replace it the easiest?

-Personally Y.A.S.I./Protector -Spinball most others I can think of are more depended on taste. -Mr. Boston and the 3D games are rare. -From my experience, rarely. -I don't know about multicarts but there is a flashcart (http://www.vectrex.biz/)

Ahh, thanks.

I don't mind going the 32x route (as I'm already on that path to some extend) but wondered if it is also fixed on a region modded 32x (as in 60Hz 32x to 50Hz switch mod made out of an 60Hz 32x)

I actually don't know but a gamecube set to 60hz, set in game, seems to have no problem. It's a modern Asus LED TV.

Yea, it's an euro (PAL) megadrive and did the language and Hertz mod. Everything seems to working fine in regular old PAL english mode but and some games work normally in PAL japanese mode but once I set it to NTSC (60hz) it all becomes black and white with once every +-2 seconds a black screen.

I've just region modded my PAL megadrive and after finishing up I noticed that when I'm playing on 60Hz it's all black and while and sometimes shows a black screen. What I've read having a SCART or 32x on top fixes it without modding. But my question is does fixes it if I put a region modded genesis 32x on top and if not a SCART cable into that 32x? Or do I have to go fiddle with an oscillator?

Bump 32x is found